<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <script src="https://cdn.staticfile.org/react/16.4.0/umd/react.development.js"></script>
  <script src="https://cdn.staticfile.org/react-dom/16.4.0/umd/react-dom.development.js"></script>
  <script src="https://cdn.staticfile.org/babel-standalone/6.26.0/babel.min.js"></script>
  <title>Document</title>
</head>

<body>
  <div id="example">

  </div>
  <script type="text/babel">
    function Tick(props) {
      return (
        <div>
          <h1>Hellow , world!</h1>
          <h2>{props.data.toLocaleTimeString()}.</h2>
        </div>
      );
    }
    function clock() {
      ReactDOM.render(
        <Tick data={new Date()} />,
        document.getElementById("example")
      )
    }
    setInterval(clock, 1000)
  </script>
</body>

</html>